pin = 0  # 存的文件指针
with open('/Users/cuixuetao/Desktop/cxt_exercise/conf/a.txt') as fr:
    fr.seek(pin)#移动指针
    for line in fr.readlines():
        print(line.split(','))
        tmp = line.split(',')
        print(tmp[0],tmp[1],tmp[2])

    pin = fr.tell()#记录已经读到了什么位置
    print(pin)

